- 學位論文
醯肼-腙衍生物的合成、異構化及其光物理性質研究
Synthesis, Isomerization and Photophysical Properties of Hydrazide-Hydrazone Derivatives
摘要
腙 (Hydrazone) 分子因具有可旋轉的N=C雙鍵結構，可藉由光驅動產生順/反異構物，因此被廣泛使用在光致發光及分子開關的應用上。在本論文中我們設計與合成一系列的醯肼-腙衍生物，探討吡啶中氮在鄰位(3a)、間位(3b)或對位(3c)時經光照反應後對分子構型的影響，我們將上述三種分子分別溶在甲醇及二甲基亞碸，實驗發現照光前後只有3a有明顯的螢光發生，且在二甲基亞碸有較高的螢光強度，而3b和3c則無螢光產生。我們利用核磁共振光譜及紅外線光譜證實3a分子經照光後會得到順式異構物，且由吸收與螢光光譜數據推得3a的順式結構可能形成分子內氫鍵使分子內轉動減少，因此可以觀察到明顯的螢光產生，此有趣的螢光變化特性將使3a分子有機會用於分子開關的一部份。 另一方面，醯肼-腙衍生物也能作為金屬傳感器，由於在生活中銅是相當豐富量的重金屬，在生物體內扮演重要的催化作用，從骨頭的形成到細胞呼吸都是其重要的一份子，因此我們使用了銅離子做為我們感測用離子，我們分別進行3a、3b和3c與銅離子螯合的研究，研究發現三種材料與銅離子作用後都有明顯螢光現象的發生，其中3a和3c在不同濃度下的螢光變化較少，而3b隨濃度增加有大幅螢光增強的現象，因此說明3b可能有分子間聚集誘導螢光的產生，我們進一步觀察在可見光、紫外光下3a、3b和3c的固體光學影像，發現只有3b在紫外光下是明亮的螢光固體，再次呼應3b為聚集誘導螢光材料，因此將有潛力作為金屬傳感器或是作為有機發光二極體的螢光材料。
關鍵字
分子開關；螢光分子；金屬螯合物並列摘要
Hydrazone molecule contains N=C double bond, which can be driven by light to produce cis/trans isomers, and it is widely used in photoluminescence and molecular switching applications. In this work, we design and synthesize a series of hydrazine-hydrazone derivatives, and explore the effect of conformational change of 3a, 3b and 3c in methanol and dimethyl sulfoxide after light irradiation. We found that only 3a has an obvious fluorescence intensity enhancement after light irradiation, especially in dimethyl sulfoxide solvent, while 3b and 3c don’t have fluorescence. We further used nuclear magnetic resonance spectroscopy and infrared spectroscopy to confirm the structure of 3a after light irradiation and cis isomerism was observed. The absorption and fluorescence spectra of 3a before and after light irradiation were also studied, these data suggest that the cis form of 3a may has intramolecular hydrogen bonds to reduce the intramolecular rotation of molecule and results in the increase of the fluorescence intensity. On the other hand, hydrazine-hydrazone derivatives can also be used as metal sensors. Because copper is a very abundant heavy metal in life, it plays an important catalytic role in organisms, such as bone formation, cellular respiration and so on. Therefore, we studied on the chelation of 3a, 3b, as well as 3c with copper ions, and the results showed that the three materials can interact with copper ions. Among them, 3a and 3c have little change of the fluorescence at different concentrations, while 3b displays a significant fluorescence enhancement with increasing in concentration. Consequently, it indicates that 3b may have intermolecular aggregation-induced fluorescence phenomenon. Furthermore, we investigate the solid-state properties of 3a, 3b, and 3c by using visible light and ultraviolet light. It is found that only 3b shows a bright fluorescent under ultraviolet light which indicates 3b is an aggregation-induced emission material, suggesting that it has the potential to be used as a metal sensor or as an organic light-emitting diode fluorescent material.